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Nurse pleads not guilty to sending menacing letters to politicians, Stephen Colbert

In the end, police say, his wife turned him in. Christopher Lee Carlson, a nurse from Vancouver, Wash., pleaded not guilty Wednesday to mailing about 100 menacing letters to members of Congress, news outlets and comedians Jon Stewart and Stephen Colbert, the Oregonian newspaper reported.

Investigators were stumped at first – the envelopes, containing a powder and postmarked from Portland, Ore., in late February, had a phony return address.

The letters said “there is a 10 percent chance you have been just exposed to a lethal pathogen.” They were signed "MAB."

Threatening letters claim ‘pathogens’ sent to senators, media

But then, in early March, Carlson and his wife were driving in Portland, according to The Columbian in Vancouver, Wash., which cited a police report. Carlson pointed at the post office and said he was worried that they had surveillance cameras pointed at them.

“Oh no, you didn’t send those letters, did you?” Adrienne Carlson said, according to The Columbian. The police report said that he told her he had and the white substance was a combination of celery salt and corn starch.

The report said he told her that he planned to send more letters that would contain lye, a caustic substance that can badly irritate skin.

When police received a report of domestic disturbance at the Carlsons' home, Adrienne Carlson told an officer that her husband had left her and that she thought he might have sent the letters, The Columbian reported.      

On March 9, according to the Oregonian, a federal grand jury in Portland indicted Carlson, finding that he had mailed letters to House Speaker John Boehner and Sen. Barbara Mikulski, a Democrat from Maryland.    

Relatives told the Oregonian that Carlson, who had spent time in psychiatric units after reporting suicidal thoughts, was disappointed because President Barack Obama had not lived up to his expectations.  

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